Characterization and application of a new ultraviolet derivatization reagent for amino acids analysis in capillary electrophoresis

A new ultraviolet (UV) labeling reagent, p-acetamidobenzenesulfonyl fluoride (PAABS-F), was designed and synthesized to label and determine the amino acids by capillary electrophoresis (CE) with diode-array detector (DAD). PAABS-F is very stable and easy to synthesize. It reacted with primary or secondary amino acids very quickly under facile conditions to give corresponding derivatives in high yield with excellent sensitivity and stability. No by-products were observed in amino acid derivatives when stored at room temperature under natural daylight for at least 7 days. Both amino acids standard solution and real samples reacted with this new UV labeling reagent smoothly to form high UV-absorption derivatives. The labeled 20 standard amino acids were efficiently separated by CE and the mass detection limits (S/N = 3) were ranged from 59.3 fmol for l-tryptophan to 1.70 pmol for l-histidine.